With development of wireless network communications technologies, a wireless fidelity (WiFi) technology is more widely applied, and an increasing quantity of terminal devices access a core network by using a WiFi access point (AP). Because quality of a signal sent by a WiFi access point and received by a terminal device is affected by factors such as a distance between the terminal device and the WiFi access point and ambient interference, to ensure that the terminal device can always well receive the signal sent by the WiFi access point and to reduce energy consumption, a transmit power of the WiFi access point needs to be adjusted. For example, when the distance between the terminal device and the WiFi access point is relatively short, the transmit power of the WiFi access point is reduced, to reduce energy consumption. When the distance between the terminal device and the WiFi access point is relatively long, the transmit power of the WiFi access point is increased, to ensure receiving quality.
Some approaches provide a power adjustment method: a current received signal strength indicator (RSSI) value of the WiFi access point is obtained at intervals of a preset time period, and the transmit power of the WiFi access point is dynamically adjusted according to the obtained RSSI value. Generally, when the distance between the terminal device and the WiFi access point is relatively short, the RSSI value is relatively large; when the distance between the terminal device and the WiFi access point is relatively long, the RSSI value is relatively small. Therefore, the terminal device can well receive the signal sent by the WiFi access point and energy consumption can be reduced by adjusting the transmit power according to the RSSI value.
However, the RSSI value can reflect only strength of a signal sent by the terminal device and received by the WiFi access point, and cannot exactly reflect a status of the signal sent by the WiFi access point and received by the terminal device. In some cases, received signal strength of the WiFi access point is extremely great, but the quality of the signal sent by the WiFi access point and received by the terminal device is extremely poor. For example, when the distance between the WiFi access point and the terminal device is extremely short, but ambient noise is extremely great, strength of the signal received by the terminal device is also extremely great, but because the noise is also extremely great, affected by the noise, the terminal device cannot well restore the signal during decoding, causing extremely poor received signal quality of the terminal device.
In such a case, the transmit power should be increased to improve the received signal quality of the terminal device. However, in the existing mechanism, the WiFi access point incorrectly determines, according to a relatively large RSSI value, that the transmit power does not need to be increased, which causes the extremely poor received signal quality of the terminal device.